Edge sharpening tool

ABSTRACT

An edge sharpening tool, particularly adapted for, but not limited to sharpening the snowside edges of snow skis. The tool comprises a handle portion and a bifurcated work portion including a pair of legs intersecting at the handle portion. A pair of blades are disposed within the work portion, one in each leg, and each blade is canted back in a direction opposite that in which the tool is normally used. The blades are arranged so that sharpening is simultaneously executed in two planes. Further the tool is so constructed so as to provide guidance and stability during the sharpening operation.

United States Patent 11 1 Winbauer 1 Oct. 23, 1973 [54] EDGE SHARPENING TOOL 2,709,379 5/1955 Murchison 76/86 0 l 7 W [75] Inventor: Alois P. Winbauer, Schenectady, 6/ 9 2 eeks 76/83 Primary Examiner0thell M. Simpson [73] Assignee: Mohawk Precision Corporation, Assistant Examiner-Gary L. Smith Schenectady, N.Y. Att0rney-James W. Mitchell 1 [22] Filed: Nov. 8, 1971 App]. N6. 196,517

[57] ABSTRACT A An edge sharpening tool, particularly adapted for, but

not limited to sharpening the snowside edges of snow skis. The tool comprises a handle portion and a bifurcated work portion including a pair of legs intersecting 6 Claims, 4 Drawing Figures EDGE SHARPENING TOOL BACKGROUND OF THE INVENTION The invention relates in general to an edge sharpen: ing tool and more particularly,the invention pertains to a tool adapted for sharpening the snowside or, steel edges of snow skis. I

In the sport of snow skiing, it is known that most skiing manuevers are accomplished by edging the ski relative to the snow. Under icy conditions, stopping and turning manuevers are particularly dependent upon well honed steel edges. The snowside edges of skis are sometimes referred to as steel edges because of a strip of steel used to form the snowside edges. The steel edge may tend to wear and become dull through frequent use and sometimes abuse and so it has become desirable to provide a convenient tool for restoring sharpness to steel edges.

Several deficiencies are prevalent in the prior art with regard to edge sharpening. One shortcoming is due to the fact that most sharpening tools operate in only one plane at a time, eg., a file. Another shortcoming in the prior art is that most ski sharpening tools do not provide a guide means or controlled sharpening and so results obtained are often haphazard and dependent upon the skill of the user. Another shortcoming of prior art is that files require considerable time to sharpen edges and that they become dull after use.

SUMMARY OF THE INVENTION An edge sharpening tool is provided with a handle portion and a bifurcated work portion. The work portion includes a pair of legs which extend outwardly in one direction and intersect at approximately a right angle in the other direction at the handle portion. A

FIG. 4 is a perspective view of the present invention as normally applied to the snowside edge ofa ski, the arrow indicating the normal direction of use.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings, the edge sharpening tool is generally indicatedat 11, having a handle portion 13 and a bifurcated work portion 15. The handle portion includes a finger recess 17 and a bevel 19, the latter being formed at the rear end of the tool. The finger recess aids in the gripping of the tool and the bevel performs a dual function of providing a pushing surface for using the tool while simultaneously insuring that the tool is being operated in the proper direction.

The work portion 15 of the tool includes a pair of legs extending outwardly at one end and intersecting at approximately a right angle at the other end, thereupon merging into the handle portion. The legs are of unequal length and therefore form a short leg and a .long leg 27. This construction allows the tool to be positioned on the ski edge so. that the short leg 25 abuts blade is partially disposed in a recess or slot in each .one

leg and each blade is oriented so that it is rotated in a direction opposing the normal direction of use,thereby providing the tool with a negative rake characteristic. The blades are so aligned within the work portion so as to provide sharpening in two planes simultaneously. The blades may also be tilted in a direction opposing the normal direction of use so that each blade may be oriented at a compound angle with respect to the direction in which the tool is normally used. The tool is provided with guide surfaces on the inside surfaces of each leg and the legs are comprised of one short leg and one long leg for stability and guidance.

It is one object of this invention to-provide an edge sharpening tool which will sharpen the ski edge in two planes simultaneously.

It is another object of this invention to provide an edge sharpening tool which will provide guidance and stability during the edge sharpening operation.

Other objects and advantages of the present invention will become apparent from the following detailed description thereof taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS the thickness of the ski while the long leg 27 abuts the snow side of the ski. This prevents the tool from pivoting about the edge of the ski. Further the tool is then guided along'the snowside of the ski by means of its abutment with the. long leg 27 of the tool.

Each leg is provided with a threaded slot 29 which preferably extends from'the line of intersection of the two legs to the extremity'of each leg. Each slot is cut at an angle to the plane of the leg in which it is formed as will be later explained. A blade 31 is partially disposed in each slot and each blade is retained in the slot by a screw 35. Other means for retaining a blade positioned withinaslot are known to those skilled in the art and are intended to be included within the scope of this invention. 1

Referring especially to FIGS. 2 and 3, each blade is partially disposed in each slot of each one leg and each blade extends toward the other leg. As is shown best in FIG. 3, each blade is rotated back in a direction opposing the direction in which the tool is normally used. Otherwise stated, each blade lies in a plane which is ap proximately normal to each other leg and which forms a dihedral angle X from a plane which is normal to the leg in which the blade is disposed. vThe dihedral angle X is inclined approximately 5 to 10 against the direction in which the tool isnormally used. This dihedral angle X is responsible for the negative rake effect of the tool. The negative rake effect is apparent as the tool is pushed along the steel edge 41 of the ski 45. (FIGA). Negative rake means that the tool will shave or scrape the ski edge rather than cause a digging or chiseling action. The slots 29 in which the blades are disposed are cut at an angle similar to the dihedral angle of the blade so as to providemaximum blade support. I

In conjunction with the negative rake" effect each leg is formed with an inside face 51 which is comprised of a concave relief 55 defined by end guide surfaces 57 which extend from both sides of the concave relief in each inside surface 51 of each leg to the extremities of each leg. The concave recess in each leg allows waste material to fall from the tool during use while the end guide surfaces provide guidance for the tool by sliding along both the snowside and the thickness of the ski. Hence, as the tool is pushed along the ski edge it is guided by these end guide surfaces and not the blades.

The blades then follow the path set by the guides rather than a haphazard path defined by the ski edges. The combination of the negative rake and the guide surfaces permits the tool to form an even well-honed ski edge.

Each blade in each leg may also be tilted in a direction opposing the normal direction of use. In other words instead of each blade lying in a plane perpendicular to each opposite leg, the blades may be tilted back at an angle Y, FIG. 3, dashed lines approximately from 5 to so that they lie in a plane which is 5 to 20 displaced from a plane normal to each opposite leg. This results in a plowing effect as waste material is swept out and away from the tool after it is shaved from the steel edge of the ski. When the tool is constructed in this manner both blades then lie in a compound angle (ie, rotated back and tilted back) with respect to each one and the other leg.

In FIG. 2, it should be observed that the blades form a double edge shaving surface which when applied to a steel edge of a ski results in a two plane simultaneous sharpening. The blades, when viewed in FIG. 2, appear to be at an angle of 90 relative to one another but it has been found that an angle of 96 will produce better sharpening. The blades, in effect, cradle the steel edge as the tool itself cradles the ski. This also produces an even, smooth honing operation since the entire ski edge at a given point along the length of the edge is sharpened.

The blades themselves may be formed from carbide or any other hardened material. One example of the type of blade material is found in Number 1050 Carboloy Blank, Grade 370 available from General Electric Company. However, there are other suitable materials available other than the above mentioned Carboloy blank.

The blades are removable from each leg of the tool by means of the screw 35 in each leg which is threaded into the slots 29. The screws may be loosened for replacement or adjustment of the blades.

OPERATION From the foregoing description of the invention, the mode of intended operation should be apparent. The tool is placed on a ski so that the short leg and the long leg respectively straddle the thickness and snowside of the ski. The tool is then pushed as the palm of the operators hand contacts the bevel provided on the handle portion of the tool. In this manner the operator will be certain that the tool is being used in the correct manner. The blades of the tool will correspondingly contact the steel edge of the ski. In operation, the blades will shave, scrape or abrade the ski edge in two planes simultaneously while being guided along by the end guiding surfaces on the inner faces of the respective legs.

The negative rake of the blades prevents the tool from digging or chiseling the steel edges. The resultant effect will be a sharpened smooth steel edge of the snow ski.

While there is shown what is considered to be the preferred embodiment of the invention, it is of course understood that various other modifications may be made therein. It is intended to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention.

What is claimed:

1. An edge sharpening tool comprising a bifurcated work portion including a pair of legs which intersect at substantially a right angle; a blade is partially disposed in a slot in each leg and extends in the direction of the other leg; each blade is rotated back, in a direction opposite the normal direction of operation, about an axis lying in the plane of each one leg and substantially perpendicular to each other leg; and, wherein each blade is tilted back, in a direction opposite the normal direction of operation, from a plane substantially perpendicular to each other leg.

2. The tool as recited in claim 1, wherein, each blade is tilted back from approximately 5 to 20.

3. An edge sharpening tool comprising a bifurcated work portion including a pair of legs which intersect at substantially a right angle; a blade is partially disposed in a slot in each leg and extends in the direction of the other leg; and, wherein each leg includes an inside surface formed with a central concave recess and flat guide surfaces, extending from either side of the recess to the end of the inside surface.

4. An edge sharpening tool comprising a handle portion and a bifurcated work portion; the work portion having a pair of legs intersecting at approximately a right angle; a blade partially disposed within each one leg and extending toward each other leg; and, each blade rotated back, in a direction opposite the normal direction of operation, about an axis lying in the plane of each one leg and substantially perpendicular to each other leg; and, further comprising one short leg and one long leg having an inside surface formed with a central concave recess bounded by a flat guide surface at each end of the inside surface.

5. The tool as recited in claim 4, wherein, each blade is tilted back, in a direction opposite the normal direction of operation, from a plane substantially perpendicular to each other leg.

6. An edge sharpening tool for sharpening a ski edge comprising a bifurcated work portion including a pair of legs which intersect at substantially a right angle; a blade is partially disposed in a slot in each leg and extends toward each other leg; and, said legs including one short leg and one long leg, said short leg always abutting the thickness of the ski. 

1. An edge sharpening tool comprising a bifurcated work portion including a pair of legs which intersect at substantially a right angle; a blade is partially disposed in a slot in each leg and extends in the direction of the other leg; each blade is rotated back, in a direction opposite the normal direction of operation, about an axis lying in the plane of each one leg and substantially perpendicular to each other leg; and, wherein each blade is tilted back, in a direction opposite the normal direction of operation, from a plane substantially perpendicular to each other leg.
 2. The tool as recited in claim 1, wherein, each blade is tilted back from approximately 5* to 20*.
 3. An edge sharpening tool Comprising a bifurcated work portion including a pair of legs which intersect at substantially a right angle; a blade is partially disposed in a slot in each leg and extends in the direction of the other leg; and, wherein each leg includes an inside surface formed with a central concave recess and flat guide surfaces, extending from either side of the recess to the end of the inside surface.
 4. An edge sharpening tool comprising a handle portion and a bifurcated work portion; the work portion having a pair of legs intersecting at approximately a right angle; a blade partially disposed within each one leg and extending toward each other leg; and, each blade rotated back, in a direction opposite the normal direction of operation, about an axis lying in the plane of each one leg and substantially perpendicular to each other leg; and, further comprising one short leg and one long leg having an inside surface formed with a central concave recess bounded by a flat guide surface at each end of the inside surface.
 5. The tool as recited in claim 4, wherein, each blade is tilted back, in a direction opposite the normal direction of operation, from a plane substantially perpendicular to each other leg.
 6. An edge sharpening tool for sharpening a ski edge comprising a bifurcated work portion including a pair of legs which intersect at substantially a right angle; a blade is partially disposed in a slot in each leg and extends toward each other leg; and, said legs including one short leg and one long leg, said short leg always abutting the thickness of the ski. 